@is_exec(value)
the predicate returns true if the argument represents an exec, that is, the instance of a compound action (e.g., the result of a process call or an object instantiation).
The predicate returns true even if the compound action has finished its computation. However, the exec itself used in a boolean condition evaluates to true if the compound action is still running and false elsewhere.
See also Predicates @!= @&& @|| @<= @< @== @>= @> @approx @arch_darwin @arch_linux @arch_windows @between @empty @find [@is_applicable] [@is_applicable_exe] @is_bool @is_defined @is_exec @is_fct @is_float @is_fct [@is_fun] @is_function @is_int @is_integer_indexed @is_list @is_map [@is_Napplicable] @is_nim [@is_not_initialized] @is_numeric [@is_paf] @is_obj @is_obj_xxx @is_prefix @is_proc @is_string [@is_string_or_symbol] @is_subsequence @is_suffix @is_symbol @is_tab @is_undef @is_vector @member @occurs